Photoelectric Properties Of Sulfide Semiconductor Nanomaterials

Because of the special photoelectric properties, the study of chalcogenide semiconductor nanomaterials has received considerable attentions in recent years. Based on this background, we tried to develop new chalcogenide semiconductor optoelectronic nanomaterials in this thesis. The research focused on the preparations and applications of fluorescent nanocrystals and one dimension photoelectric nanomaterials. The main details include the following items:1. Microwave-assisted Synthesis of Highly Luminescent AgInS2/ZnS Nanocrystals for Dynamic Intracellular Cu(II) DetectionLow-toxic, highly luminescent, and water-soluble AgInS2/ZnS nanocrystals (NCs) have been synthesized via a microwave-assisted approach. The structure and optical features of the AgInS2/ZnS NCs were characterized by X-ray diffraction, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet visible absorption spectroscopy, and photoluminescence (PL) spectroscopy. The as-synthesized AgInS2/ZnS NCs exhibited high PL quantum yields (40%) and long PL lifetimes (424.5 ns). Furthermore, the dynamic changes of the intracellular copper (Ⅱ) levels in HeLa cells were monitored using the AgInS2/ZnS NCs as fluorescent probes. The results showed that the AgInS2/ZnS NCs as promising fluorescent probes could be used in the detection of intracellular copper ions in living cells.2. Aqueous Synthesis of Color-tunable CuInS2/ZnS Nanocrystals for Detection of Human interleukin-6In this chapter, we presented a facile microwave-assisted synthetic route for the preparation of water-soluble and high quality CuInS2/ZnS nanocystals (NCs) with glutathione as the stabilizer. The as-prepared CuInS2/ZnS NCs exhibited small particle sizes (～3.3 nm), long photoluminescence lifetimes and color-tunable properties from visible to near-infrared by varying the initial ratio of Cu:In in precursors. The low-toxic, highly luminescent, and biocompatible CuInS2/ZnS NCs were applied to cell imaging, showing that they could be used as the promising fluorescent probes. Furthermore, the CuInS2/ZnS NCs were used as the signal labels for fluoroimmunoassay of the biomarker IL-6, showing their great potentials for reliable point-of-care diagnostics of cancer and other disease biomarkers.3. Individual HfS3 Nanobelt for Field-effect Transistor and High Performance Visible-light DetectorHfS3 nanobelts were directly synthesized via a simple chemical vapor transport method. A field-effect transistor and photodetecor was further fabricated based on an individual HfS3 nanobelt, and its electrical and optoelectronic properties were evaluated, respectively. The output characteristic curves of the FET revealed a typical p-type semiconducting behavior. The photodetector has an ultralow dark current (0.04 pA) and a large on/off ratio (337.5) illuminated by 405 nm light with 1.2 mW/cm2. It demonstrated excellent stability and sensitivity to 405 nm light. The results suggested that the HfS3 nanobelts are promising for applications in nanoscale electronic and optoelectronic devices. The research will play a positive role in nanodevice research of one-dimensional transition-metal trichalcogenide nanostructure.4. The photodetector based on individual ZrSe3 or HfSe3 nanobeltIn this chapter, ZrSe3 and HfSe3 nanobelts were directly synthesized via chemical vapor transport method. Both photodetecors were further fabricated based on an individual ZrSe3 and HfSe3 nanobelts, and their optoelectronic properties were evaluated, respectively. The individual ZrSe3 or HfSe3 nanobelt photodetector showed excellent photoelectries. In addition, the electron transport property of individual ZrSe3 nanobelt was studied at different temperature. In the low temperature (10 K), the ZrSe3 photodetecor also showed excellent photoelectric properties.